In the house of the wise are stores of choice food and oil, but a foolish man devours all he has (Proverbs 21:20).
What is the best -- most godly -- strategy for resource management? The Bible clearly encourages radical generosity and living by faith, trusting that God will supply whatever we need whenever we need it (see Matthew 6, among other passages, for further elaboration on these themes). But it's also interesting to note that the Proverbs regularly point out the God-given wisdom of planning ahead, deliberately saving one's most basic resources, and living on a modest margin in case any type of calamity should strike.
So how do we balance this line of living by faith and practicing wise stewardship of the resources which God has entrusted to us?
On this point, I am absolutely convinced that each individual / household needs to come to their own convictions about how to manage their resources -- and then make a deliberate plan to live by their personal convictions. But in the midst of making such decisions, I would suggest that it might be wise to include Proverbs 21:20 in the mix. From this verse, one could draw the conclusion that the basic costs for food and utilities / shelter (i.e. "choice food and oil") should be kept in reserve. A three-month reserve of all housing, utilities, and food costs could potentially be a practical outworking of this Proverb. But this is really just a starting point for consideration...
A complete study of the Bible's teachings on resource management make it obvious that neither extreme is healthy. Compulsive, self-centered consumption is foolish. But so is compulsive, self-sufficient hoarding is not good either. Neither of these extremes represent the life of faith. True godliness and wisdom is somewhere in between. Clearly, some level of storage / savings / reserves is wise. But how much -- that's between you and God.